Image-data reduction technique
Filter-subtract-decimate hierarchical pyramid signal analyzing and synthesizing technique
Method and apparatus for coding an image
Image data processing of correlated images
Method of and apparatus for compressing image data
Tile-oriented technique for collectively performing image rotation, scaling and digital halftone screening
Method and apparatus for encoding/decoding image data
Spline-wavelet signal analyzers and methods for processing signals
Digital data compression system including zerotree coefficient coding
Method for fusing images and apparatus therefor
ApplicationNo. 557475 filed on 11/14/1995
US Classes:382/233, Including details of decompression375/240.08Feature based
ExaminersPrimary: Bost, Dwayne D.
Assistant: Johnson, Brian L.
Attorney, Agent or Firm
International ClassesG06K 009/42
AbstractImage compression and viewing are implemented with (1) a method for performing DWT-based compression on a large digital image with a computer system possessing a two-level system of memory and (2) a method for selectively viewing areas of the image from its compressed representation at multiple resolutions and, if desired, in a client-server environment. The compression of a large digital image I(x,y) is accomplished by first defining a plurality of discrete tile image data subsets Tij (x,y) that, upon superposition, form the complete set of image data I(x,y). A seamless wavelet-based compression process is effected on I(x,y) that is comprised of successively inputting the tiles Tij (x,y) in a selected sequence to a DWT routine, and storing the resulting DWT coefficients in a first primary memory. These coefficients are periodically compressed and transferred to a secondary memory to maintain sufficient memory in the primary memory for data processing. The sequence of DWT operations on the tiles Tij (x,y) effectively calculates a seamless DWT of I(x,y). Data retrieval consists of specifying a resolution and a region of I(x,y) for display. The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT, the output of which forms the image display. The repeated process whereby image views are specified may take the form an interaction with a computer pointing device on an image display from a previous retrieval.
Field of SearchIMAGE COMPRESSION OR CODING
Pyramid, hierarchy, or tree structure
Highpass filter (i.e., for sharpening or enhancing details)
Lowpass filter (i.e., for blurring or smoothing)
To change the scale or size of an image
IMAGE TRANSFORMATION OR PREPROCESSING
Selecting a portion of an image